🔧 Fusion - Serpentine Belt Replacement

The serpentine belt drives key accessories on your Fusion, such as the alternator, A/C compressor, and water pump. Replacing it means releasing spring tension from the belt tensioner, removing the old belt, routing the new belt correctly, and checking that it sits fully in every pulley groove.

Difficulty Level: Beginner | Estimated Time: 0.5-1.0 hours

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⚠️ Safety & Precautions

• ⚠️ Work only with the engine completely off and cool.
• ⚠️ Keep fingers, clothing, and tools away from pulleys and the belt path.
• ⚠️ Disconnecting the battery is recommended because your hands will be near rotating engine accessories.
• ⚠️ Do not start the engine until the belt is fully seated on every pulley.
• ⚠️ Support the hood securely before working in the engine bay.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 3/8-inch drive ratchet
• 3/8-inch drive breaker bar
• 15mm socket
• Serpentine belt tool (specialty)
• Flat-blade screwdriver
• Flashlight
• Safety glasses
• Mechanic gloves

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Serpentine drive belt - Qty: 1

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📋 Before You Begin

• Park your Fusion on level ground and shift to Park.
• Set the parking brake.
• Open the hood and let the engine cool fully.
• Use a flashlight to look for the belt routing decal under the hood or near the radiator support.
• If the routing decal is missing, take a clear photo of the old belt path before removal.
• Use a 10mm socket and 3/8-inch drive ratchet to disconnect the negative battery cable. Move the cable aside so it cannot touch the battery post.
• A belt tensioner is a spring-loaded pulley arm that keeps the belt tight automatically.
• A serpentine belt tool is a long, thin handle that gives extra reach and leverage in tight engine spaces.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Locate the Belt and Tensioner

• Use a flashlight to look at the passenger side of the engine where the belt loops around the pulleys.
• Find the spring-loaded belt tensioner pulley. It will be the pulley mounted on a movable arm.
• Compare the current belt path with the belt routing decal or your photo.
• Tip: Photograph everything before touching it.

Step 2: Check the New Belt Before Removal

• Place the new serpentine drive belt next to the old belt path and confirm it is the same rib style and similar length.
• Use your hands and safety glasses for this inspection.
• Do not remove the old belt until you are confident the new belt matches.

Step 3: Release Belt Tension

• Install the 15mm socket onto the serpentine belt tool or 3/8-inch drive breaker bar.
• Place the 15mm socket on the center bolt of the belt tensioner pulley.
• Rotate the tensioner slowly to relieve belt tension. On this Fusion, the tensioner arm will move against spring pressure.
• Hold the tensioner steady with the serpentine belt tool while you slide the belt off the easiest smooth pulley.
• Keep your fingers away from the gap between the belt and pulley.

Step 4: Remove the Old Belt

• Slowly let the tensioner return to its resting position using the serpentine belt tool.
• Remove the old belt from the remaining pulleys by hand.
• If the belt catches on a splash shield edge, gently guide it with a flat-blade screwdriver.
• Do not pry hard against plastic pulleys or wiring.

Step 5: Inspect the Pulleys

• Use a flashlight to inspect each pulley before installing the new belt.
• Spin the smooth idler pulleys by hand if accessible. They should spin smoothly without grinding or wobbling.
• Look for oil, coolant, or shredded belt material on the pulleys.
• If a pulley is seized, loose, noisy, or coated with oil, fix that problem before installing the new belt.

Step 6: Route the New Belt

• Route the new serpentine drive belt around the pulleys by hand using the belt routing decal or your photo.
• Make sure the ribbed side of the belt sits on grooved pulleys.
• Make sure the smooth back side of the belt sits on smooth pulleys.
• Leave the easiest smooth pulley for last so the belt is easier to slip on after releasing the tensioner.
• Tip: Grooves must match grooves.

Step 7: Reapply Tension and Seat the Belt

• Use the 15mm socket and serpentine belt tool to rotate the tensioner again.
• Slide the belt over the final pulley by hand.
• Slowly release the tensioner until it tightens the belt.
• Use a flashlight to check every pulley. The belt ribs must sit fully inside the pulley grooves.
• If the belt is one rib off, use the serpentine belt tool to release tension again and reposition it before starting the engine.

Step 8: Reconnect the Battery

• Use the 10mm socket and 3/8-inch drive ratchet to reconnect the negative battery cable.
• Tighten the battery terminal snugly. Do not overtighten it.
• Torque to 5 Nm (44 in-lbs) if using a torque-capable tool.

Step 9: Start and Observe

• Remove all tools from the engine bay.
• Start the engine and let it idle.
• Use a flashlight to watch the belt from a safe distance.
• The belt should run straight with no squeal, flap, smoke, or wobble.
• Turn the engine off immediately if the belt walks off a pulley or makes a loud noise.

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✅ After Repair

• Let the engine idle for 1-2 minutes and listen for squealing or chirping.
• Turn on the A/C and headlights to load the accessories, then listen again.
• Shut the engine off and recheck belt alignment with a flashlight.
• After a short drive, recheck the belt path once more with the engine off.
• If you disconnected the battery, you may need to reset the clock and one-touch window functions if they lost memory.

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💰 DIY vs Shop Cost

Shop Cost: $140-$260 (parts + labor)

DIY Cost: $25-$70 (parts only)

You Save: $115-$190 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.5-1.0 hours.

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🎯 Ready to get started?

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